%%
%% The LaTeX Companion, 3ed
%%
%% Example 16-3-32 on page II-502 in "biblatex's approach to author-date references".
%%
%% Copyright (C) 2022 Frank Mittelbach
%%
%% It may be distributed and/or modified under the conditions
%% of the LaTeX Project Public License, either version 1.3c
%% of this license or (at your option) any later version.
%%
%% See https://www.latex-project.org/lppl.txt for details.
%%

\documentclass{tlc3exa}
\pagestyle{empty}
\setcounter{page}{6}
\setlength\textwidth{183.0pt}

% Use biber program
\setlength\parindent{0pt}

%StartShownPreambleCommands
\usepackage[style=authoryear,
   citetracker=true,maxnames=2]{biblatex}
\addbibresource{tlc.bib}
\AtEveryCitekey{%
  \ifciteseen{}{\setcounter{maxnames}{99}}}
%StopShownPreambleCommands

\begin{document}
\textcite{LGC97} \\ \textcite{LGC97}
\end{document}
